Home security systems have become popular recently among general homeowners for the purposes of preventing damage and losses caused by an unauthorized person and monitoring rooms to detect an abnormal condition caused by disasters, such as fire. Such home security systems include terminal devices, such as a sensing unit that detects an unauthorized person entering a house from a window or door or detects an abnormal condition in a room and a camera unit for capturing images of an intruder.
These terminal devices are controlled by a main control device, namely a main controller. The main control device specifies identifying information, such as an ID number, given to each terminal device to identify the individual terminal devices and controls the corresponding terminal devices. To this end, the identifying information of each terminal device needs to be registered with the main control device prior to the first use. In addition, identifying information of the main control device also needs to be registered with each terminal device so that the terminal devices can identify the main control device.
Such home security systems are categorized into a self-installation type involving purchase of the system by a general user and a professional-installation type. The former type requires the user, who purchased the system, to register identifying information of each terminal device with a main control device and to register identifying information of the main control device with each terminal device. The registration of the identifying information can be conducted by operating both an operation unit, like a registration switch, of the main control device and an operation unit, like a registration switch, of the each terminal device; however, the same steps have to be repeatedly conducted to register the identifying information of each terminal device with the main control device, which is burdensome for the user.
Japanese unexamined patent publication No. 2005-223791 describes a monitoring system that automatically registers identifying information of terminal devices with a main control device upon recognizing the placement of a battery in the terminal devices.
In the monitoring system of publication No. 2005-223791, the identifying information of the terminal devices can be registered with the main control device by placing the battery into the terminal devices; however, the registration of the identifying information of the terminal devices cannot be made by operating the main control device so as to make a request for the transmission of the identifying information.